First reports came in at Google Groups yesterday afternoon. The report read as follows:

At the moment the Traffic Estimator gives no or almost no data for e.g. German or Italian keywords. The English data works fine. This is definitely not the usual statistical uncertainties but completely missing data chunks for whole languages.

The issue has been verified and confirmed by Google AdWords representative who said, "Yes, I can confirm - this was a known issue, seen by a number of advertisers, which you should now find to be resolved." But the issue is not resolved, at least not currently. According to advertisers, the numbers reported are about 100 times lower then what one might expect.